UMEM Educational Pearls

Title: Using a Micropuncture Kit for Difficult Lines

Keywords: vascular access, micropuncture kits, procedures (PubMed Search)

Posted: 10/15/2024 by Cody Couperus-Mashewske, MD
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Getting reliable venous and arterial access is crucial when resuscitating critically ill patients. These lines can be difficult due to patient and situation specific variables.

Micropuncture kits contain a 21-gauge echogenic needle, a stainless-steel hard shaft/soft-tip wire, and a 4 Fr or 5 Fr sheath and introducer. The micropuncture kit offers several advantages that can help overcome difficult situations:

Small, Sharp Needle: Easier puncture of compressible vessels.
Echogenic Design: Improved visibility under ultrasound.
Smooth Tissue Penetration: Moves through tissue more easily than a typical 18-gauge needle.
Flexible Wire Tip: The 0.018-inch wire is soft, lacks a J-loop, and navigates tight corners and calcifications better than a standard J-tip wire. This is especially useful when entering at a steep angle or accessing small vessels.

To use a micropuncture kit, gain vessel access with the needle and wire, railroad the sheath and introducer into the vessel, remove the wire, then remove the introducer. Now you have a 4 Fr or 5 Fr sheath in the vessel. This is typically used to introduce a normal central line wire.

For arterial lines, you can place them directly over the wire without dilation. Keep in mind that the 4 Fr sheath (1.3 mm OD) and 5 Fr sheath (1.7 mm OD) are larger than a typical arterial line catheter (18g = 1.27 mm OD). If you dilate then you will cause hematoma.

Find out where your department stores micropuncture kits and get familiar with their components. While it adds an extra step to the procedure, it could make the difference between securing the line or not.

References

Montrief, T., Ramzy, M., & Long, B. (2021). Micropuncture kits for difficult vascular access. The American journal of emergency medicine.